Measles‑Induced Immunosuppression and Tuberculosis Reactivation: Evidence‑Based Guidelines

Immunologic Basis of Tuberculin Reactivity

• The tuberculin skin test (TST) depends on a delayed‑type hypersensitivity (DTH) response that normally becomes detectable 2–12 weeks after primary Mycobacterium tuberculosis infection. [CDC MMWR Recommendations and Reports] 1

Vaccination Recommendations for Persons with Active Tuberculosis

• The CDC advises that antituberculous therapy should be started before administering measles‑containing vaccines to individuals with untreated active tuberculosis, because of a theoretical risk that measles‑induced immunosuppression could exacerbate TB disease. [CDC MMWR Recommendations and Reports] 2

• Observational data reported by the CDC indicate that patients already receiving appropriate TB treatment have not experienced disease exacerbations after receipt of the measles‑mumps‑rubella (MMR) vaccine, suggesting that effective therapy mitigates the theoretical risk. [CDC MMWR Recommendations and Reports] 2

Tuberculin Testing Guidance in the Context of MMR Vaccination

• According to CDC guidance, routine tuberculin skin testing is not a prerequisite for MMR vaccination in individuals without active tuberculosis, because transient anergy during measles infection does not reflect true absence of latent infection. [CDC MMWR Recommendations and Reports] 2